Electric switching apparatus



1931- M. c. 1. HUNTER ET AL 1,837,968

I ELECTRIC SWITCHING APPARATUS Filed Dec. 22, 1928 Invehcors: Marcus 0.1. Hunter: Francis LhFle tcheT? Their Attorney.

Patented Dec. 22,1931

UNITED JSTA i m GARDEN, AN'ID FRAJNOIB LEONARD LBBIGNORS 1'0 GENERAL ELECTRIC COM- ELECTRIC SYRTI'ZEG KIILWG APZPARA'IUB Application filed December 22, 1928, Serial No. 8

Our invention relates .to electric switching apparatus, particularl of the type in who a main current control ing switch is mounted in a movable structure having isolating contacts which are adapted to engage cooperating contacts in a fixed structure. The object of ourinvention is the provisioaof switchin apparatus of this character having improve means for covering the contacts of the fixed structure when the movable structure is withdrawn therefrom'and for automatically operating the contact covering means in response to the movement of the movable structure.

Our invention will be better understood from the following description taken in con nection with the accompan ing drawings, and its scope will be pointe out in the appended claims. v

Referring to the drawin s, Fig. 1 is an elevation partly in section o a switching apparatus involving our invention with the movable structure thereof in its lowered or isolated position; Fig. 2 is an end view'of the same with parts broken away to more clearly show its construction; Figs. 3 and 4 are views similar respectively to Figs. .1 and 2 but with the movable structure in its raised or connected position.

The apparatus by which we have chosen to illustrate our invention comprises the three single pole oil switches 1, 2 and 3 secured together by the frame 4 to form a unitary movable structure. The several switches 1, 2 and 3 itwill be noted are shown arranged with their insulator bushings 5 in alinement and resting on the top of each switch is the adapter 6 having a pair of upward extensions 7 arranged transversely of the switch unit and having the isolating terminals 8 thereon. The terminals 8 connect by suitable conductors in the adapter with the terminals on the respective insulator bushings 5. It isto be understood that the use of adapters 6 is not essential to apparatus involving our inventionsince if desired the oil switches may be provided with insulator bushings spaced apart a suflicient distance to engage the cooperating isolating contacts. Where, however, standard switches are to 27,771, and in Great Britain January 19, 1928.

be'used the spacing of the insulator bushings of whlch not great enough, we prefer to employ adapters such for example as those illustrated.

Coo crating with the movable structure thus escrlbe is the fixed structure 10 into which the former is arranged to be raised by means forming no part of the present invent1on and which in the interest of clearness has been omitted from. the drawings. The structure 10 comprises a plurality of separate compartments 11' each containing an insulating 1qu1d such as oil and havin in its bottom the spout 12. The end of eae spout is open and secured thereto is the hollow conical insulator 13. A fixed isolating terminal 14- is secured to the upper end of each insulator and to each of t ese terminals connects the bus bar or phase conductor 15.

For covering and rotecting the fixed iso lating contacts 14 w ion the movable structure is 1n 1ts lowered position or when it is removed therefrom, as for exam le, for inspection or repair, we have provi ed shutter devices each com rising two segments 17 pivoted at 18 tot e end" spouts 12 and arranged when in closed position to make a tight connection with the respective spout openings. Each segment is shown rovided at one end with the projecting pin 19 y which it is operated. Adjacent the pins 19 and secured to the fixed structure 10 are the brackets 20 in which is slidably mountedthe shutter operating rodsor spears 22. Brackets 20 also have extensions 23, the purpose of which presently will be described; At the lower end of each spear 22 there is pivoted the latch 24 which by means of the spring 25 connecting it with the spear is yieldingly held in the inoperative position when the main switches are in their lowered or disconnected postion as shown in Fig. 1. When the main switch structure is raised from the position shown in Fig. 1 to that shown in Fig. 2, the projection 26 on the frame 4 engages the end of the spear and raises it also. In this upward movement the upper end of the spear which preferably is somewhat pointed engages the pins 19 on the shutter segments and gives to the segments a rapid opening move- TES PATENT OFFICE ment. ,The spear thereafter continues to slide between the pins upon continued upward movement of the main switch structure, In

the initial upward movement of the spear thelatch 24- engages the extension 23 and is rotated thereby against the spring 25 to a position such as that shown in Fig. 2 in which position it interlocks the spear and the projection 26. VV hen the main switch structure is lowered away from the fixed structure, the spear, by reason or its being interlocked with the former structure is positively lowered therewith until the upper end of the spear passes beyond the pins 19 and the latch reaches the end or. the extension 23 when it is swung by spring 25 away from the extension 26. The main switch structure may then be further lowered or entirely removed if desired without afiectin the shutter operating mechanism. Upon the replacement; of the main switch structure or the substitution of a similar one, the same when raised with the cooperating isolating contacts in proper alinement will engage and operate thespear in the manner already described. The two shutter segments oi each pair naturally gravitate to the closed position. If it is deemed advisable, however, the force of gravity may be su plemented by the use of suitable springs attac ed to the segments. To prevent the spears "from dropping out of their supporting brackets when the main switch structure is removed each is shown provided-with the stop pin 27.

What we claim as new and desire to secure by Letters Patent of the United States, is:

1. Electric switching apparatus comprising fixed and movable structures having cooperating contacts, a contact covering demos and an o crating member therefor mounted on said xed structure, and means insuring,

ositive actuation of said operating member mcluding a latching device carried by said operating member arranged to engage a portion of the movable structure when the same reaches a certain point in its movement toward the fixed structure and to become disengaged therefrom when it is withdrawn beyond a certain point.

2. Electric switching-apparatus comprising fixed and movable structures having cooperating oontacts,,a contact covering shutter and an operating rod therefor mounted on the fixed structure, and means insuring pos1- tive actuation of said operatin rod including a latching device arranged to interlock with, a portion of the movable structure when the same reaches a predetermined point in its movement toward the fixed structure and to become released therefrom when the movable structure is withdrawn beyond a predetermined point.

3. Electric switching apparatus comprising a fixed contact supporting structure, a

movable switch supporting structure having ing operating permanently mounted on the a contact adapted to engage the contact of the fixed structure, a shutter device mounted on the fixed structure and arranged to cover the contact thereof, a shutter operating member arranged in the path of movement of a portion ofjthe movable structure to be moved thereby, and means insuring positive actuation of said shutter operating member including a latch carried by said operating member arranged to be moved by its engagement with a portion of the fixed structure to a position interlocking with said portion ot' the movable structure. 4%. Electric switching apparatus comprising" a stationary contact supporting structure, a movable contact supporting structure, a contact covering device comprising a pair of shutter segments pivotully mounted on the stationary structure and engaging each other in the contact isolating position, a pin connected to each of said shutter segments, and a segment operating member slidably mounted within a guide on the stationary structure and arran ed to be positively actuated by said mova )le structure,.said segment operating member initially engaging said pins and subsequently passing between the same to cause opening of said shutters in opposite directions priorto movement of the movable contacts therethrough. 5. Electric. switching-apparatus comprising a fixed contact supporting structure, a movable contact supporting structure, a shutter adapted to cover the contacts of the fixed structure comprising a pair of segments pivoted to the fixed structure and havprojections thereon, a spear fixed structure for limited longitudinal movement and an ranged initially to engage said projections and move the segments to a position uncovering the contacts and subsequently to pass freely between the pro'ections, said movable contact supporting structure having a disengageablc connection with said spear.

In witness whereof, we have hereunto set our hands this 4th day of December. 1928.

MARCUS CHARLES lNMAN HUNTER. FRANCIS LEONARD FLETCHER. 

